The tanker space vessel Nostromo receives a distress signal from a nearby planet and proceeds with a rendezvous. But once there, the group discovers a most vicious alien lifeform hellbent on its own survival...by eliminating its guests one by one.

Owes much to past monster on the loose pictures such as It! The Terror From Beyond Space (1958) and Howard Hawks' The Thing (1951), not to mention Bava's chilling and atmospheric Planet of the Vampires (1965).